Strap breaking device



June 21, 1955 H. A. GILLSTROM STRAP BREAKING DEVICE Filed Sept. 18, 1952 ATTORNEYS United States STRAP BREAKING DEVICE Harold A. Gillstrom, La Grange, 111., assignor to Gustave Hdseen, Incorporated, Chicago, IlL, a corporation of l inois Application September 18, 1952, Serial No. 310,304

5 Claims. (Cl. 81-3) This invention pertains to strap breaking devices.

It is now common to bind objects with steel bands or straps which are drawn up tightly about the object and the ends securely clamped together, thus leaving the strap under considerable tension. An example of the use of such straps is in the binding of crates for shipment and storage. minimum expense and yet provide maximum tensile strength, the straps are customarily made of steel or the like which is difiicult to part easily. Thus, there is a great demand for devices of simple design which may be quickly and conveniently employed to break the straps when the object is to be unbound. Many attempts have been made to provide shearing devices and other means for breaking the straps, but it is considered that no successful and yet simple and inexpensive device is presently known.

By the present invention, there is provided a very inexpensive device for breaking straps, having no moving parts and not otherwise subject to wear or destruction of any sort. Briefly, the present invention is embodied in a device having a body portion with parts extending from the body portion to form an opening therebetween. A strap under tension is placed within the opening. and the body and extending parts rotated in a direction to place the portion of the strap Within the opening at such an angle to the adjacent portions of the strap'that the strap'breaks along at least one edge of one of the extending parts. Preferably, the extending parts will be closely adjacent and the opening therebetween best defined as a slit.

Accordingly, the primary object of this invention is to provide an improved strap breaking device.

A further object of this invention is to provide an improved strap breaking device having no moving parts.

A further object=of this invention is to provide a strap breaking device having a slit for receiving a strap under 7 tension with means beingprovided for rotating the slit to break the strap along at least one edge thereof.

A further object of this invention is to provide a strap breaking device having an opening for receiving a strap under tension, the opening being so arranged and/or positioned that breaking of the strap begins at one edge thereof and then proceeds across the strap.

I Anobject of this invention is to provide a strap breaking device having an opening for receiving a strap under tension, the opening being between two extending parts of a bifurcated cone, so that breaking of the strap begins at one edge thereof and then proceeds across the strap.

Further objects and the entire scope of the invention will become further apparent from the following detail description and from the appended claims.

The invention may be best understood by reference to the accompanying drawings, in which:

Figure 1 shows the device of the present invention as placed in operative relationship to a strap on a shipping crate.

Figure 2 shows a side elevational view of the device of the present invention.

To make such straps available at a 2,711,109 Patented June 21, 1955 ice Figure 3 shows a front elevational view of thedevice of the present invention.

Figure 4 shows a perspective view of a portion of the device of the present invention.

Figure 5 shows a front elevational view of a portion of the device of the present invention in a first operative position, and A Figure 6 shows a front elevational view of the device of the present invention in a second operative position.

Referring now to the drawing, the strap breaking device comprises a body portion 10 having afiixed there to at the left hand end, as viewed in Figure 2, two ex- ".ending parts 12 and 14 which define a slit or opening 16 therebetween. Attached to the opposite end of body 10 is any suitable handle 18. Y

As shown in Figure 1, the device is employed by placing it in such position that a strap 2.0 bound under tension about crate 22 is within the slit 16 with the longitudinal axis of the strap substantially at right angles to the longitudinal axis of the body 10 and extending parts 12 and 14, all as shown. Alternatively, the axis of the body 10 and parts 12 and 14 may be at an angle substantially different from a right angle, as will be described below. Usually, but not necessarily so,*'the lower extension 14 and/or the lower point of the body 10 will rest on the surface of crate 22.

To break the strap 20, the handle 18 may be moved in a direction substantially parallel to the direction of the strap 20 to rotate the slit 16 from the position shown in Figures 3 and 5 to the position shown in F-igure 6. It is now thought apparent, considering the strap to be under considerable tension, that severe bending of the strap willoccur at the edges 24 of the extending parts 12 and 14 which define the slit. So long as these edges are relatively sharp, that is, have a relatively short radius of curvature, the minimum bending angle of the strap 20 will be exceeded and the strap will break. Theoretically, where both sides of the extending parts 12 and 14 are of identical configuration, the strap 20 should break at both ends of the portion of the strap 20' within the slit 16. However, in practice, it is usual that some minor difference will cause the strap to part at one end of strap portion'20 and not atboth ends simultaneously.

In the illustrated embodiment, as shownin the drawing, the body portion 10 of the device iscylindrical and the extending parts 12 and 14 taken together define a cone with the slit 16 actually dividing the cone in a central plane thereof. There are several advantages to this particular construction, as will be described fully below. However, broadly, it is to be understood that the body 10 and extending parts 12 and 14 need conform to no particular cross-sectional'or longitudinal design. All that is required is that the opening or slit for receiving the strap-be so arranged that, upon operation of the handlels as described, the portion of the strap 20' within the slit will be moved to an angle with respect to the adjacent portions of the strap, so that the severe bending of the strap at the edges 24 will cause breakage. It will be noted in this connection, asshown in Figure 6, that it is only the right edge. 24 on extending part 12 over which the strap is bent to cause breakage. Thus, it will be apparent that the unused edges could be dispensed with to a certain extent and all that is required is that at least what will be termed a breaking pair of edges of the extending parts be available for the bending action and only one edge of the pair need be sharp enough to cause breakage.

Referring again to the particular constructional embodiment illustrated in the drawings, this embodiment is deemed to be preferable for several reasons. First, with the body portion cylindrical and the extending parts 12 and 14 forming a cone, the device may be readily rolled on the surface of crate 22, although the breaking action will occur Without a supporting surface. Moreover, the circular nature of the parts lends them to easily machining, forging or casting. Most important, however, is the fact that with the slit 16 terminating within the conical section, or at least terminating no further than the base thereof, the most severe bending of the strap 20 will occur only at one edge of the strap. That is, in Figure 4, severe bending will occur first at the root 16' of the slit. Due to the converging configuration of the slit, the strap will not bend as severely to begin with toward the apex of the cone, since it will tend to bend in a direction substantially at right angles to the longitudinal dimension of the strap. As best shown in Figure 4, the severe bend is at the point of the strap designated 26, while the curvature of bend will be more gradual at the point of the strap designated 28. In practice, it is found that the strap actually breaks or tears along the edge 24 and thus the resulting break is found to be at an angle, as is the broken edge designated 30 in Figure 4.

The fact that the break begins at one edge of the strap and proceeds thereacross is an important feature of this invention, inasmuch as extremely heavy straps may be broken by a device of minimum strength. This is so be cause the starting force, which is the maximum force, is applied at root 16 of the slit. As stated, this may be just at the base of the cone formed by extending parts 12 and 14. On the other hand, if the breaking edge were to extend in a direction at right angles to the lengthwise dimension of the strap, the device must create the severe bend completely across the strap at the same instant and thus more force must be applied by the user of the device and also the extensions 12 and 14 must be heavier to withstand the increased forces being applied outwardly from the root 16 of the slit. Since the extensions 12 and 14 are mounted in cantilever fashion in body 10, this becomes important. It is found, moreover, that the tearing action requires less force than would a break straight across the strap, the nature of the tearing break requiring less force than a break resulting from a complete break across the strap.

It will, of course, be understood that the extending parts 12 and 14 need not form a cone in order to achieve the advantages of the tearing break just described. The

same result may be achieved by having the extending parts 12 and 14 be of cylindrical or any other crosssectional and longitudinal design, so long as the device when used is placed so that the selected breaking edge 24 is at an angle to the longitudinal dimension of the strap. For example, the root 16' of the slit may be at an angle so that the device may be pushed over the strap and the root 16 seated along the edge of the strap. Also, the operator may simply see to it that the device is positioned to have an edge 24 at an angle to the strap, regardless of whether or not the strap is seated against the root 16' of the slit.

Broadly, so long as at least the two opposite edges 24 of the respective parts 12 and 14, which form the above-mentioned breaking pair, are not parallel, a correct positioning of the device for a tearing break is automatically insured.

The nose end of the lower extending part 14 may be bevelled as at 32 to permit this part to be readily slipped beneath the staple and the handle 18 then moved rear-,

wardly to pivot the device about point 34 to move said nose end of part 14 upwardly to pull the staple from its seat in the package.

It is to be understood that the foregoing detailed description of the illustrated specific embodiment of the invention is not intended to limit the scope of themvention. On the contrary, the true scope of the invention is to be determined from the appended claims.

I claim:

1. A strap breaking device comprising, a body portion having extending parts which define a longitudinal- 1y extending opening therebetween from a free end thereof for longitudinally receiving a strap under tension, means for turning said body about its longitudinal axis to cause a portion of the strap lying between said extending parts to be drawn against exterior longitudinal edges of the opening, one side of the strap being drawn against a first longitudinal edge on one of said extending parts, and the other side of said strap being drawn against a second longitudinal edge on the other of said extending parts, said first and second longitudinal edges being on opposite transverse sides of said body, said first and said second longitudinal edges defining lines which are diverging, at least one of said longitudinal edges being sharp.

2. A device as in claim 1 in which the exterior longi tudinal surfaces of said extending parts definea circular peripheral cross section.

3. A device as in claim 1 in which said extending j sponding edges on the same transverse side of the extending parts being parallel, the edges on the opposite transverse sides of the extending parts being divergent,

whereby rotation of said body portion about its longitudinal axis will cause an uneven tensile stress upon a tensed strap extending transversely through the slot.

5. A strap breaking device comprising a body portion, means for rotating said body portion about its longitudinal axis, a projection having its free end tapered, said projection extending longitudinallyfrom said body portion and having a slot extending from the free end thereof towards said body portion for receiving a strap.

References Cited in the file of this patent UNITED STATES PATENTS 264,696 Hillard Sept. 19, 1882 717,735 Cofiin Jan. 6, 1903 927,653 Heckman July 13, 1909 1,173,026 Petermann Feb. 22, 1916 1,290,431 Waite Jan. 7, 1919 2,593,663 Fanelli Apr. 22, 1952 

